Republican Senator Dan Sullivan has sought to have a namesake primary challenger removed, citing the potential for confusion in the midterms.

A judge in Alaska has ruled that an incumbent United States senator and a challenger with the same name can both appear on a midterm primary ballot.

The decision means that both Republican Senator Dan Sullivan and his namesake opponent, former US Forest Service worker and retired teacher Dan Sullivan, are both eligible in the August 18 primary.

“Mr ⁠Dan Sullivan is declared to be an eligible candidate,” Superior Court Judge Thomas Matthews said in the ruling, referring to the challenger.

The decision reversed an earlier move by the director of the Alaska Division of Elections.

Republican Party officials had argued that the appearance of two Dan Sullivans on the ballot could confuse voters.

Some, including Senator Sullivan, have also alleged that challenger Sullivan had been recruited by Democrats to boost Democratic Senate candidate Mary Peltola.

A spokesman for Peltola, a former US representative, told The Associated Press that she has had no involvement in either Sullivan campaign.

Republicans are expected to appeal the ballot decision to the state’s Supreme Court.

Alaska has a single ballot non-partisan primary system. Unlike in other states where Democrats and Republicans hold separate contests to determine which candidates will face off in the general election in November, all candidates, regardless of party, appear on Alaska’s primary ballot sheet.

The top four contenders then move on to the general election.

Advocates have said Alaska’s primary system forces primary candidates to appeal to a broader portion of the state’s electorate, and not just members of their party.

Democrats are hoping to wrest control of the US House of Representatives and US Senate from the Republicans in November’s midterm election.

Winning a majority in either chamber of Congress would dramatically shift the political equation in the country, likely reducing President Donald Trump’s legislative power in the final two years of his term.